Ship shafting automatic positioning device based on machine vision

Abstract

The utility model belongs to the technical field of ship construction, and particularly relates to a positioning device in a ship shafting installation process, in particular to a ship shafting automatic positioning device based on machine vision, which comprises a tail target, a horizontal adjusting mechanism, a machine vision detection module, an automatic leveling module, a vertical adjusting mechanism and an industrial personal computer, the machine vision detection module is arranged right in front of the tail target and comprises a machine vision camera, the visual field range of the machine vision camera comprises all areas of the tail target, and the machine vision camera is connected with the fixing plate through a magnetic type universal rod; the laser theodolite is placed right above the leveling execution mechanism, the tail target is arranged at a shafting positioning target position, and the laser theodolite is arranged at a position which is 6m-15m away from the tail target. Through cooperative work of automatic leveling, machine vision detection and servo drive adjustment, the full-process automation of ship shafting positioning is achieved, the defects of a traditional method are effectively overcome, and the ship shafting positioning system has remarkable practical value.

Description

Technical Field

[0001] This utility model belongs to the field of shipbuilding technology, and in particular relates to a positioning device in the process of ship shafting installation, specifically an automatic positioning device for ship shafting based on machine vision. Background Technology

[0002] The ship's shafting is a core component of the ship's propulsion system, and its positioning accuracy directly affects the ship's navigation stability, power transmission efficiency, and equipment lifespan. Traditionally, ship shafting positioning relies on manual operation of a laser theodolite for benchmark calibration. The specific process involves manually adjusting the laser theodolite's level, which heavily depends on the level and the operator's experience. The laser direction is calibrated by visually observing the overlap between the laser spot and the stern tube's reference point, and then manually adjusting the stern target position to align the laser spot with the target's center point.

[0003] The above-mentioned traditional methods have the following drawbacks:

[0004] 1. Low efficiency: The manual leveling, calibration and position adjustment steps are cumbersome and time-consuming.

[0005] 2. High labor intensity: It requires multiple people to operate and relies on repeated manual adjustments.

[0006] 3. Accuracy depends on experience: The leveling and tail target positioning of the laser theodolite both depend on the operator's skills, and human error can easily lead to insufficient positioning accuracy.

[0007] 4. Poor consistency: Differences in experience among different operators may lead to inconsistent shaft positioning results, affecting the quality of subsequent installation.

[0008] Therefore, there is an urgent need for a ship shafting positioning device that can achieve automated positioning, reduce reliance on manual labor, and improve efficiency and accuracy. Summary of the Invention

[0009] This invention aims to solve the problems of low efficiency, high labor intensity, reliance on manual experience, and insufficient accuracy in existing ship shafting positioning processes. This invention provides an automatic ship shafting positioning device based on machine vision, which achieves automatic leveling of the laser theodolite, automatic laser path calibration, and automatic adjustment of the stern target position, thereby improving positioning efficiency and accuracy while reducing labor intensity. The technical problem to be solved by this invention is achieved through the following technical solution:

[0010] An automatic positioning device for ship shafting based on machine vision includes a stern target, a horizontal adjustment mechanism, a machine vision inspection module, an automatic leveling module, a vertical adjustment mechanism, and an industrial control computer. The horizontal adjustment mechanism includes a guide rail and a stern target fixing slider. The stern target fixing slider is slidably connected to the guide rail, and the stern target is fixedly connected to the stern target fixing slider. The guide rail is fixedly connected to a fixed plate. The machine vision inspection module is located directly in front of the stern target and includes a machine vision camera. The field of view of the machine vision camera covers the entire area of ​​the stern target, and the machine vision camera is connected to the fixed plate via a magnetic universal joint. The automatic leveling module includes a gyroscope, a controller, and a leveling actuator. The controller is positioned above the leveling actuator, and the gyroscope and leveling actuator are electrically connected to the controller. A vertical adjustment mechanism is positioned below the automatic leveling module, and the leveling actuator is fixedly connected to the vertical adjustment mechanism. A laser theodolite is positioned above the automatic leveling module, directly above the leveling actuator, and fixed by four-sided limiters. The vertical adjustment mechanism is driven by a first servo motor, and the horizontal adjustment mechanism is driven by a second servo motor. The first servo motor, the second servo motor, and the controller are electrically connected to an industrial control computer. The tail target is positioned at the axis positioning target location, and the laser theodolite is positioned 6m-15m away from the tail target.

[0011] Furthermore, the laser path of the laser theodolite must coincide with two preset reference points at the front end of the ship's stern tube.

[0012] Furthermore, the vertical adjustment mechanism is a ball scissor screw jack.

[0013] Furthermore, the gyroscope is a MEMS gyroscope sensor with an accuracy of ≥0.1°.

[0014] Specifically, the leveling actuator consists of three sets of electric outriggers driven by stepper motors, with an outrigger extension accuracy of ±0.1mm.

[0015] Specifically, the tail target is made of aluminum alloy with a white matte coating; the horizontal line is a black engraving with a width of 0.2mm, which is consistent with the theoretical horizontal direction of the axis system; the center point is a cross engraving with a diameter of 0.5mm, which corresponds to the theoretical end position of the axis system.

[0016] Specifically, the distance between the machine vision camera and the tail target is 200mm-500mm.

[0017] Even better, the lens axis of the machine vision camera is at a 15-degree angle to the surface of the tail target.

[0018] Even better, the machine vision camera is an industrial camera with a resolution of 5 megapixels and an 8mm fixed-focus lens.

[0019] Even better, the controller is an STM32 microcontroller, and the industrial computer is a PLC automatic control system.

[0020] This utility model has the following beneficial effects:

[0021] 1. High degree of automation: The automatic leveling module enables one-click leveling of the laser theodolite, and the machine vision inspection and servo motor driven adjustment mechanism enable automatic calibration of the tail target position, reducing manual intervention.

[0022] 2. Significantly improved efficiency: Eliminates the tedious steps of repeatedly leveling and manually adjusting the tail target, greatly shortening the positioning cycle.

[0023] 3. Reduce labor intensity: No continuous manual operation is required; positioning can be completed simply by starting the device, reducing manpower input.

[0024] 4. Eliminating reliance on experience: Precise detection and adjustment are achieved through machine vision and automatic control, avoiding errors caused by differences in human experience, resulting in higher positioning consistency and accuracy.

[0025] 5. Easy to operate: One-click start for automatic leveling, and subsequent adjustments are fully automated, suitable for operators of different skill levels. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of this utility model;

[0027] Figure 2 Here are schematic diagrams of the horizontal and vertical adjustment mechanisms;

[0028] Figure 3 This is a schematic diagram of the tail target and the machine vision camera.

[0029] Figure 4 This is a structural diagram of the automatic leveling module and the vertical adjustment mechanism. Detailed Implementation

[0030] Combination Figures 1 to 4 As shown, an automatic positioning device for ship shafting based on machine vision includes a stern target 101, a horizontal adjustment mechanism, a machine vision detection module, an automatic leveling module, a vertical adjustment mechanism, and an industrial control computer 601. The horizontal adjustment mechanism includes a guide rail 201 and a stern target fixing slider 202. The stern target fixing slider 202 is slidably connected to the guide rail 201, and the stern target 101 is fixedly connected to the stern target fixing slider 202. The guide rail 201 is fixedly connected to a fixing plate 203. The machine vision detection module is located directly in front of the stern target 101 and includes a machine vision camera 301. The field of view of the machine vision camera 301 covers the entire area of ​​the stern target 101. The machine vision camera 301 is connected to the fixing plate 203 via a magnetic universal joint 302.

[0031] The automatic leveling module includes a gyroscope 401, a controller 402, and a leveling actuator 403. The gyroscope 401 and the controller 402 are positioned above the leveling actuator 403, and the gyroscope 401 and the leveling actuator 403 are electrically connected to the controller 402.

[0032] A vertical adjustment mechanism is set below the automatic leveling module, and the leveling actuator 403 is fixedly connected to the vertical adjustment mechanism. A laser theodolite 501 is set above the automatic leveling module. The laser theodolite 501 is placed directly above the leveling actuator 403 and is fixed by four-sided limit. The vertical adjustment mechanism is driven by the first servo motor 705, and the horizontal adjustment mechanism is driven by the second servo motor 204.

[0033] The first servo motor 705, the second servo motor 204, and the controller 402 are electrically connected to the industrial control computer 601. The tail target 101 is set at the target position of the axis system, and the laser theodolite 501 is set at a distance of 6m-15m from the tail target. In this embodiment, the laser theodolite 501 is set at a distance of 8m from the tail target.

[0034] In this embodiment, the laser theodolite 501 is a high-precision laser theodolite (such as Leica TS60), whose laser range meets the positioning distance requirements of the ship's shafting (usually 5-50 meters), and the laser spot diameter is ≤0.5mm to ensure positioning accuracy; the laser path of the laser theodolite 501 needs to coincide with two preset reference points at the front end of the ship's stern tube to ensure that the laser extends along the theoretical axis of the shafting.

[0035] The vertical adjustment mechanism is a ball scissor lift (such as SWL10), including a lead screw 701, a slide rail 702, a scissor lever 703, and a platform 704. The first servo motor 705 drives the lead screw 701 to slide the slide rail 702, thereby moving the scissor lever 703, thus realizing the lifting and lowering of the platform 704. The lead screw stroke is 100mm, and the transmission accuracy is ±0.02mm. The first servo motor 705 is an AC servo motor with an encoder, which is connected to the lead screw through a reducer to achieve an adjustment accuracy of 0.01mm / step.

[0036] The gyroscope 401 is a MEMS gyroscope sensor with an accuracy of ≥0.1°, which can output the pitch and roll angles of the laser theodolite 501 in real time; the leveling actuator 403 consists of three sets of electric outriggers, driven by stepper motors. The stepper motors are electrically connected to the controller 402, and the outrigger extension accuracy is ±0.1mm; the controller 402 is an STM32 microcontroller. After receiving the signal from the gyroscope 401, it controls the extension and retraction of the electric outriggers through a PID algorithm to achieve a leveling accuracy of ≤0.02mm / m.

[0037] The tail target 101 is made of aluminum alloy with a white matte coating. The horizontal line is a black engraving with a width of 0.2mm, which is consistent with the theoretical horizontal direction of the axis system. The center point is a cross engraving with a diameter of 0.5mm, which corresponds to the theoretical end position of the axis system.

[0038] The distance D between the machine vision camera 301 and the tail target 101 is 200mm-500mm. The lens axis of the machine vision camera 301 is at a 15-degree angle to the surface of the tail target 101. The machine vision camera 301 is an industrial camera with a resolution of 5 megapixels and an 8mm fixed-focus lens. In this embodiment, the distance D between the machine vision camera 301 and the tail target 101 is 300mm. The machine vision camera 301 acquires the laser spot and center point image from the surface of the tail target 101 and compares the coordinate positions through the image processor.

[0039] In this embodiment, the guide rail 201 is a high-precision linear guide rail with a length of 500mm and a parallelism of ≤0.01mm / m; the sliding resistance between the tail target fixing slider 202 and the guide rail 201 is ≤5N; the second servo motor 204 drives the tail target fixing slider 202 to move via a synchronous belt with a movement accuracy of ±0.01mm.

[0040] In this embodiment, the vertical adjustment mechanism is fixed on the tripod 901 on the fixed plate 203 and the fixed bracket 801. The industrial control computer 601 is installed in the electrical box. The industrial control computer 601 is a PLC automatic control system. The industrial control computer 601 is equipped with an image processor. In this embodiment, the image processor is an NVIDIA Jetson Nano. It identifies the center coordinates of the laser spot through the OpenCV algorithm, compares them with the horizontal line (y coordinate threshold) and center point (x0, y0) of the tail target 101, and calculates the deviation (Δx, Δy). The deviation detection accuracy is ≤0.01mm.

[0041] After receiving the deviation signal (Δx, Δy) from the image processor, the industrial control computer 601 outputs pulse signals to control the first servo motor 705 and the second servo motor 204: when Δy≠0, the first servo motor 705 is driven to adjust the lifting mechanism until Δy=0; when Δx≠0, the second servo motor 204 is driven to adjust the slider position until Δx=0, thus completing the positioning.

[0042] The working process of this utility model is as follows:

[0043] Step 1: Start the device. The gyroscope 401 of the automatic leveling module detects the horizontal status of the laser theodolite 501. The controller 402 drives the leveling actuator 403 to operate, and the horizontal calibration of the laser theodolite 501 is completed with one click.

[0044] Step 2: Adjust the laser emission direction of the laser theodolite 501 so that the laser beam passes through the two reference points at the front end of the tail shaft tube in sequence (ensuring that the laser is along the theoretical axis of the axis system), and the laser beam continues to be directed toward the tail target 101.

[0045] Step 3: The machine vision camera 301 acquires the laser spot image on the tail target 101, and the image processor analyzes whether the spot coincides with the horizontal line of the tail target 101.

[0046] If they do not coincide, the image processor calculates the vertical deviation and sends it to the industrial control computer 601. The industrial control computer 601 drives the first servo motor 705 to adjust the vertical position of the laser theodolite 501 through the lifting mechanism until the light spot coincides with the horizontal line.

[0047] Step 4: After completing the vertical calibration, the image processor continues to analyze whether the laser spot coincides with the center point of the tail target 101.

[0048] If they do not coincide, the image processor calculates the horizontal deviation and sends it to the industrial computer 601. The industrial computer 601 drives the second servo motor 204, which drives the tail target fixing slider 202 to move horizontally along the guide rail 201 until the light spot coincides with the center point, thus completing the axis positioning.

[0049] In summary, this invention achieves full automation of ship shafting positioning through the coordinated operation of automated leveling, machine vision inspection, and servo drive adjustment, effectively solving the drawbacks of traditional methods and possessing significant practical value.

[0050] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. An automatic positioning device for ship shafting based on machine vision, characterized in that, The device includes a tail target, a horizontal adjustment mechanism, a machine vision inspection module, an automatic leveling module, a vertical adjustment mechanism, and an industrial control computer. The horizontal adjustment mechanism includes a guide rail and a tail target fixing slider. The tail target fixing slider is slidably connected to the guide rail, the tail target is fixedly connected to the tail target fixing slider, and the guide rail is fixedly connected to a fixing plate. The machine vision detection module is located directly in front of the tail target and includes a machine vision camera. The field of view of the machine vision camera covers the entire area of ​​the tail target. The machine vision camera is connected to the fixed plate via a magnetic universal joint. The automatic leveling module includes a gyroscope, a controller, and a leveling actuator. The gyroscope and the controller are positioned above the leveling actuator, and the gyroscope and the leveling actuator are electrically connected to the controller. A vertical adjustment mechanism is provided below the automatic leveling module, and the leveling execution mechanism is fixedly connected to the vertical adjustment mechanism. A laser theodolite is provided above the automatic leveling module and is placed directly above the leveling execution mechanism, with four-sided limiting fixation. The vertical adjustment mechanism is driven by a first servo motor, and the horizontal adjustment mechanism is driven by a second servo motor. The first servo motor, the second servo motor, and the controller are respectively connected to the industrial control electromechanical system. The tail target is set at the target position of the axis system, and the laser theodolite is set at a distance of 6m-15m from the tail target.

2. The automatic positioning device for ship shafting based on machine vision according to claim 1, characterized in that, The laser path of the laser theodolite must coincide with two preset reference points at the front end of the ship's stern tube.

3. The automatic positioning device for ship shafting based on machine vision according to claim 1, characterized in that, The vertical adjustment mechanism is a ball scissor screw jack.

4. The automatic positioning device for ship shafting based on machine vision according to claim 1, characterized in that, The gyroscope is a MEMS gyroscope sensor with an accuracy of ≥0.1°.

5. The automatic positioning device for ship shafting based on machine vision according to claim 1, characterized in that, The leveling actuator consists of three sets of electric outriggers driven by stepper motors, with an outrigger extension accuracy of ±0.1mm.

6. The automatic positioning device for ship shafting based on machine vision according to claim 1, characterized in that, The tail target is made of aluminum alloy with a white matte coating. The horizontal line is a black engraving with a width of 0.2mm, which is consistent with the theoretical horizontal direction of the axis system. The center point is a cross engraving with a diameter of 0.5mm, which corresponds to the theoretical end position of the axis system.

7. The automatic positioning device for ship shafting based on machine vision according to claim 1, characterized in that, The distance between the machine vision camera and the tail target is 200mm-500mm.

8. The automatic positioning device for ship shafting based on machine vision according to claim 7, characterized in that, The lens axis of the machine vision camera is at a 15-degree angle to the surface of the tail target.

9. The automatic positioning device for ship shafting based on machine vision according to claim 7, characterized in that, The machine vision camera is an industrial camera with a resolution of 5 megapixels and an 8mm fixed-focus lens.

10. The automatic positioning device for ship shafting based on machine vision according to claim 1, characterized in that, The controller is an STM32 microcontroller, and the industrial computer is a PLC automatic control system.

Images